High-frequency tube tuning system



Oct. 14, 1958 ALLEN 2,856,557

HIGH-FREQUENCY TUBE TUNING SYSTEM Filed Oct. 14, 1955 2 Sheets-Sheet 1IN VEN TOR. Ross/er 944 EN BY 5 Oct. 14, 1958 ALLEN 2,856,557

HIGH-FREQUENCY TUBE TUNING SYSTEM Filed Oct. 14, 1955 2 Sheets-Sheet 2INVENTOR.

United States Patent Qfice 2,856,557 Patented Oct. 14, 1958HIGH-FREQUENCY T UllE TUNING SYSTEM Robert Allen, Lexington, Mass,assignor to the United States of America as represented by the Secretaryof the Air Force Application October 14, 1955, Serial No. 540,659

3 Claims. (Cl. 315-547) (Granted under Title 35, U. 5. Code (1952), sec.266) The invention described herein may be manufactured and used by orfor the United States Government for governmental purposes withoutpayment to me of any royalty thereon.

The present invention relates generally to means for tuninghigh-frequency tubes and as illustrated herein relates more particularlyto a construction which maintains diaphragms of the resonant tubecavities of such tubes in substantial parallelism throughout the tuningrange.

011eobject of the present invention is to provide a construction by theuse of which the tuning of a highfrequency tube having hollow resonatorsmay be quickly and conveniently accomplished. To this end, the tube hasclamped thereto a tuning device which is arranged to be fixed to a pairof peripheral flanges on the tube which in turn are connected todeformable diaphragms forming end walls of the hollow resonators whichform a part of the evacuated envelope of the tube in such a manner thatthe diaphragms are maintained in symmetrical relation during the entireextent of the tuning movement.

Another object of the invention is to improve generally upon theconstruction and operation of devices for tuning high-frequency tubes.

Other objects and features of the invention will appear hereinafter fromthe following description when read with reference to the accompanyingdrawings which illustrate a preferred embodiment of the invention and inwhich:

Fig. 1 is a view, partly in section, taken along the line I'-I of Fig.2;

Fig. 2 is a sectional view taken along the line of ll-ll; and

Fig. 3 is a view, partly in section, taken along the line II IIII ofFig. l.

The present invention is concerned with an improved tuning device for ahigh-frequency tube iii having on closed hollow resonators and which isoperable not only as a self-oscillator but may also be operated as anamplifier and detect-or as well.

The tube ll) as shown in the drawing is of the super high-frequencyvelocity modulation type having a pair of resonant cavities 12, idhaving deformable end walls 16 and 18, respectively. The end walls 316and 18 are connected to rigid flanges 2b, 22;, respectively, by reducedneck portions 24 and 26, as shown in Fig. 1 of the drawing. Movement ofthe flanges 2b and 22 in opposite directions will impart equal movementto the end walls 16 and 18.

In order to impart proper tuning movement to the flanges END, 22, by atuning device which is so con structed and arranged that the deformableend walls or diaphragrns in, 1 18 are held in symmetrical relation toeach other at all times during the tuning operation, the tuning device28 is provided with right and left housing members 3%, 32, which, asbest shown in Fig. 2, are secured to upper and lower supporting brackets34, 36 which in turn are fixed to a supporting panel 3 3.

The Klystron tube is provided with a peripheral flange 40 which isclamped to a plate 42 by segments 44, 4-6 (Fig. 3). The plate 42 issecured to the end housing 32 by shouldered spacer posts 48, 50. Asshown best in Fig. l, the outer end of each post 48, 50 is reduced indiameter to receive a bearing ill) for a gear 104, as will later bedescribed, and to provide shoulders 56 which serve also as abutments tolimit movement ofthe movable tuning plates 5% and 60 toward each other.The posts dd, 5b are very carefully and accurately machined to insurethat the plates 53, 6% will be absolutely parallel to each other whenthe plates are engaged with the shoulders or ahutments 56. The posts 38,5b are each secured to their respective end plates or housings 3t 32 bysuitable machine screws 62.

The tuning mechanism illustrating a preferred form of the presentinvention comprising a tuning knob 64- afiixed to one end of the shaft66; the shaft at its inner end portion (Fig. 3) being mounted in spacedbearings 68 which are formed on a supporting bracket 70 secured to theplate 2. by machine screws 72. The shaft 66 has pinned thereto a Worm'74 which is located between the bearings ss and which meshes with aworm gear 76 affixed to a shaft 78 by a suitable pin till. The shaft '73is held from endwise movement in one direction by a spacer member whichbears at one end against the hub of the Worm gear in and its other endbears against the spur gear lid aflixed to the left hand and of theshaft 78. Endwise movement in the other direction is prevented by asleeve as having its right hand end against the spur gear 88 clamped tothe right hand end portion of the shaft 725, as will later be described.The sleeve as is held in position on the shaft 78 by a collar 89. Thespur gears 8 till mesh with internally toothed ring gears dd, 92,respectively. The ring gears W, 92, as shown best in Fig. l, arerotatably supported within the end casings 32. As shown, the ring gearsare supported within the end casings by bearings dd, 96, which arerotatably secured to the ring gears at spaced locations by bolts lllZ.The bearings 5, as engage the inner peripheral surfaces of theirrespective housings 3f), 32. As shown, the ring gears are maintained inaxial position within their respective housings by the studs or bolts98, 101 which are of substantially the same length as the inner axialdimension of each of the housings 3Q, 32. With the construction justabove described, the ring gears 94, 96 are free to rotate within theirrespective housings when the tuning knob 6 is rotated in one directionor the other. The spur gears 84, are identical and the teeth thereon areprecision cut, as are the internal teeth on. each of the ring gears. 98and E92. Thus, back lash between the various sets of meshing gears isreduced to a minimum.

Reference heretofore has been made to plates 58, 60 which are providedwith axially disposed openings to receive threaded hub portions of spurgears 2104, The construction an assembly of each of these spur gearunits libe 1% are substantially identical and hence it will be necessaryto describe only one of these assemblies in detail.

Referring now to Fig. 1 of the drawing, the spur gear 104 is shown insection as having its teeth meshing with the ring gear 92. The spur gear104 is provided with an outwardly extending shouldered portion whichbears against the inner wall of the housing 32 and is provided with aninwardly extending hub port-ion 108 which is threaded into a threadedopening 112 formed in the plate 60. In order to reduce friction betweenthe rotating spur gear 104 and the post 48, an anti-friction bearing 110surrounds the reduced outer end portion of the post 48. The housing 32is secured to the post 48 by a suitable machine screw 113. As shown inFig. 2, there are three gears 104 which mesh with the ring gear 90.Likewise the plate 58 is provided with three threaded openings forreceiving the threaded hub portions of the gears 106. It is to be notedthat the hubs of the gears 104 and 106 are oppositely threaded so thatthe plates 58 and 60 will simultaneously move toward and away from eachother a fixed distance depending upon the rotation of the tuning knob64.

The plates 58 and 60 are clamped to the axially displaced flanges 20 and22 hereinbefore referred to by means of clamping segments 114 and 116,respectively. Thus, as the plates 58 and 60 move toward and away fromthe other the flanges 20 and 22 will likewise move toward and away fromeach other, depending upon the direction of rotation of the tuning knob64. As previously stated,

the diaphragms 16, 18 are connected to the flanges 20, '22 by reducedneck portions 24 and 26 in such a manner that movement of the flanges 20and 22 will be imparted to the deformable end walls or diaphragms 16,18. The end walls 16 and 18 may be provided with spaced corrugations topermit deformation and displacement of the end walls 16 and 18 withoutdanger of ultimate breakage thereof.

Reference has heretofore been made to clamping the spur gears 84, 88which are mounted on the shaft 78. As shown most clearly in Fig. 1, thespur gear 88 at the right hand end of the shaft 78 is provided with anoutwardly extended hub portion having a shoulder which is arranged toengage the inner face of the end wall of the housing 32. The hub iscontinued outwardly beyond the housing 32 through an opening therein andis provided with an intermediate threaded portion 120 and a beveledportion 122 which is split to permit the hub to be securely clamped tothe shaft 78. A clamping nut 124 is shown as provided with a threadedportion and a beveled portion coinciding with the bevel 122 on the hubof the spur gear 88. Thus when the clamping nut 124 is threaded on tothe hub of the spur gear 88, the gear 88 will be rigidly clamped to theshaft 78 by the clamping action of the coacting beveled faces on the nutand on the spur gear. The left hand end of the shaft is provided with aspur gear 84 which is provided with a hub portion which is identicalwith the hub portion of the gear 88, as described above. During initialassembly of the parts the flanges 20 and 22 are parallel to each otherby being assembled with the clamping plates 58 and 60 with the platesbearing against the shoulders of the spacer posts 48 and 50 ashereinbefore described. After the posts have been thus assembled, theclamp nut 124 is tightened to lock or clamp the spur gear 88 intolocking engagement with the shaft 78. The clamping nut 126 at the lefthand shaft 78 having previously been tightened to lock the gear 84 tothe shaft 78, both spur gears are now fast on the shaft 78 and arerotated as a unit. Thus since the plates 58 and 60, which are rigidlyconnected to the flanges 20 and 22 to the deformable end walls ordiaphragms 16 and 18 of the resonant tube cavities, are initiallyparallel they will remain parallel throughout the extent of tuningmovement due to precision machining of the coacting elements of thetuning mechanism.

The above description is merely illustrative and is not intended todefine or limit the present invention but is for purposes ofillustration only.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. A tuning device for high-frequency tubes having a pair of spacedevacuated hollow resonators and deformable walls associated with each ofsaid resonators, said tuning device comprising means for rigidlysupporting said tube, a pair of members arranged for movement toward andaway from each other and each having a plurality of threaded openings,means for connecting said pair of members to the deformable ends of saidtubes to impart movement to the deformable end walls of said spacedresonators, a plurality of gears threaded into said members to impartaxial movement thereto and to said connecting means, a ring gear coupledto each of said members and meshing with they plurality of gears abovereferred to, and driving gears meshing with said ring gears and fixed toa single shaft for imparting rotary movement to said ring gears wherebysaid deformable end walls may be moved toward and away from each otherto tune said tube.

2. A tuning device for a high-frequency tube having a pair of spacedevacuated hollow resonators and deformable walls associated with each ofsaid resonators, said device comprising means for rigidly supportingsaid tube including a flat plate clamped to an intermediate portion ofsaid tube, a pair of parallel plates arranged for movement toward andaway from each other having threaded openings therein, means forconnecting said last mentioned plates to said deformable walls of saidhollow resonators, gears having threaded hubs entering the threadedopenings in said plates, a ring gear coupled to each of said plates forrotating said gears, and means interconnecting said ring gears formoving said plates and the said deformable walls connected theretotoward and away from each other.

3. A tuning device for high-frequency tubes having a pair of spacedhollow resonators and deformable walls associated with each of saidresonators, said tuning device comprising a rigid frame for supporting atube, a pair of plates mounted in said frame and arranged for movementtoward and away from each other and having threaded openings therein,means for connecting said pair of plates to said tube to impart movementto the deformable end walls of said spaced resonators, a plurality ofgears having hub portions threaded into said plates to impart axialmovement thereto as said gears are rotated, a separate .ring gearcoupled to each of said members and meshing with the plurality of gearsabove referred to, and driving gears fixed to a single shaft and meshingwith said ring for imparting rotary movement to said ring gears wherebysaid deformable end walls may be moved toward and away from each otherto tune said tube.

References Cited in the file of this patent UNITED STATES PATENTS2,263,184 Mouromtsetf et al. Nov. 18, 1941 2,293,152 Litton Aug. 18,1942 2,496,535 Hoglund et al. Feb. 7, 1950 2,658,393 Woods Nov. 10, 19532,757,312 Hansen et al. July 31, 1956

